Image enlargement/reduction processor and method

A method of enlarging or reducing an image, comprising the steps of:

• adding picture data on the basis of a conversion multiplying factor of a density of picture elements which are arranged in a matrix having two scanning directions, in synchronization with a clock signal along one of the two scanning directions, to produce added picture data and a carry signal;
• temporarily holding a picture element data array along one of the two scanning directions;
• outputting at least two contiguous picture element data among the data array;
• dividing a section defined by said contiguous picture element data into a plurality of sub-sections;
• obtaining typical values corresponding to each sub-section from the picture element data;
• selecting only one value from among the typical values in accordance with the added data of the adding step;
• and
• outputting the contiguous picture element data and adding the picture data in accordance with the carry signal and selection data for determining whether a reduction conversion or an enlargement conversion should be carried out.

An image enlargement and reduction processor, comprising:

• cumulative adding means for cumulatively adding picture data, the picture data being dependent on a conversion multiplying factor of a density of picture elements arranged in a matrix having two scanning directions, and for outputting added picture data and a carry signal;
• contiguous picture element output means for temporarily holding a picture element array along one of the two scanning directions and outputting at least two contiguous picture element data;
• typical value calculation means for dividing the contiguous picture element data into sub-sections and obtaining typical values corresponding to each sub-section;
• typical value selecting means for selecting and outputting only one value from the typical values dependent on the added picture data;
• and control means for controlling the output of the contiguous picture element output means and the addition of the picture data by the cumulative adding means dependent on the carry signal and externally supplied selection data.